Banker John Delaney knew that Maryland's ruling Democrats had someone else in mind to become the state's next 6th District congressman.

But the 48-year-old multimillionaire from Potomac jumped into the race anyway. And despite early missteps, Delaney's campaign appears to be gaining momentum with just over a week to go before the April 3 Democratic primary.

In the past month, he has won endorsements from former President Bill Clinton and The Washington Post, among others. His campaign has reported raising more than $767,000 in donations this year — a significant haul for a congressional race.

He's put an additional $1.3 million of his own money into the campaign.

It was partly the sense that leading Maryland Democrats were backing state Sen. Rob Garagiola that prompted Delaneyto run for the seat, which represents Western Maryland and portions of Frederick and Montgomery counties. Those who know Delaney say the risk he is taking — and the reason he's taking it — are consistent with the types of decisions he's made throughout his life.

"The notion that the party had already selected its candidate did inspire me," Delaney said. "Sometimes taking on the machine is as principled a notion as what you want to do."

Whoever wins the nomination will face Republican Rep. Roscoe G. Bartlett in November, assuming the 10-term incumbent prevails in his own primary fight. The 6th District, which was redrawn last year by Democrats in Annapolis, is among a handful nationwide that will determine which party controls the House of Representatives.

Delaney, chairman of the Chevy Chase bank CapitalSource, has argued that his business credentials make him the best candidate to tackle unemployment. He has advocated for overhauling the nation's tax code, investing in infrastructure and creating a path to citizenship for illegal immigrants.

But he faces significant hurdles. Chief among them is that all of the state's most powerful unions are backing Garagiola. That union support could prove crucial to getting voters to the polls for what will likely be a low-turnout election.

Delaney, who is married and has four daughters, grew up in a blue-collar New Jersey neighborhood in the shadow of Giants Stadium. He worked construction jobs with his father during summers and visited with friends whose first-generation grandparents from Italy and Poland lived in the basement and spent evenings cooking in the kitchen.

Good grades and a scholarship from his father's electricians union — a scholarship he often notes on the campaign trail — got him into Columbia University, where he studied biology. Unsettled by medicine as a career, he followed roommates to Georgetown Law, where he met his wife.

But Delaney gave up on the safety of a legal career and lept into business instead.

He bought a small health care company, retooled its operations, and sold it for a profit. In 1993, he co-founded HealthCare Financial Partners, a company that lent money to nursing homes and doctors. He took it public three years later, becoming the youngest CEO in the history of the New York Stock Exchange at age 32.

He made millions when he sold the company in 1999. Instead of walking away from work, he founded CapitalSource in 2000 and led it as CEO for nearly a decade. The commercial and retail bank, which had $8.3 billion in assets at the end of last year, makes loans to small and medium-sized businesses.

Despite Delaney's intense pace — he carries three BlackBerry devices — friends describe him as remarkably detail oriented, both at work and in his relationships.

David Bradley, chairman and owner of Atlantic Media, which includes The Atlantic magazine, describes how Delaney once found him rummaging in the kitchen at a party in search of an iced tea. Now, Delaney personally delivers one without being asked whenever they're together at a party.

"John is tribal in his affections," Bradley said.

Delaney, a Catholic, describes himself as "very religious" but acknowledges that his political views sometimes conflict with the church. For instance, he says he supports the Obama administration's recent requirement that insurance companies provide contraceptive coverage for religious employers, even if they object. Delaney sits on the board of directors of Georgetown University, a Jesuit institution.

His opponents have pressed him to publicly repudiate the university's position on contraception.

Though he is running as a political outsider, Delaney has donated and raised hundreds of thousands of dollars for Democratic candidates and the party. His campaign says he raised about $800,000 for then-Sen. Hillary Clinton's unsuccessful presidential bid in 2008.

And while his work at CapitalSource gives Delaney the mantle of "job creator" on the campaign trail, it also has provided a steady stream of ammunition for opponents. Garagiola's campaign has combed through the company's vast and complicated transactions, noting that it is being audited by the IRS over an arrangement conceived under Delaney's leadership that allowed it to pay less federal tax.

Delaney aides notethat audits are routine and do not imply wrongdoing.

Broadly, Delaney's opponents have tried to paint him as a Wall Street banker who is using his wealth to buy the competitive seat. He's worth at least $50 million, which would make him among the richest members of Congress if elected.

For his part, Delaney resists the idea that his wealth is a political liability.

"I wasn't born with a silver spoon," he said. "I took risks, I created businesses and I created jobs. "